fix(typing): all problems by mypy

patterns/behavioral/catalog.py

@@ -77,7 +77,8 @@ def main_method(self) -> None:
 
         depending on self.param value
         """
-        self._instance_method_choices[self.param].__get__(self)()
+        self._instance_method_choices[self.param].__get__(self)()  # type: ignore
+        # type ignore reason: https://github.com/python/mypy/issues/10206
 
 
 class CatalogClass:
@@ -115,7 +116,8 @@ def main_method(self):
 
         depending on self.param value
         """
-        self._class_method_choices[self.param].__get__(None, self.__class__)()
+        self._class_method_choices[self.param].__get__(None, self.__class__)()  # type: ignore
+        # type ignore reason: https://github.com/python/mypy/issues/10206
 
 
 class CatalogStatic:
@@ -151,7 +153,8 @@ def main_method(self) -> None:
         depending on self.param value
         """
 
-        self._static_method_choices[self.param].__get__(None, self.__class__)()
+        self._static_method_choices[self.param].__get__(None, self.__class__)()  # type: ignore
+        # type ignore reason: https://github.com/python/mypy/issues/10206
 
 
 def main():

patterns/behavioral/chain_of_responsibility.py

@@ -19,13 +19,11 @@
 """
 
 from abc import ABC, abstractmethod
-from typing import Optional, Tuple, TypeVar
-
-T = TypeVar("T")
+from typing import Optional, Tuple
 
 
 class Handler(ABC):
-    def __init__(self, successor: Optional[T] = None):
+    def __init__(self, successor: Optional["Handler"] = None):
         self.successor = successor
 
     def handle(self, request: int) -> None:
@@ -55,6 +53,7 @@ def check_range(request: int) -> Optional[bool]:
         if 0 <= request < 10:
             print(f"request {request} handled in handler 0")
             return True
+        return None
 
 
 class ConcreteHandler1(Handler):
@@ -66,6 +65,7 @@ def check_range(self, request: int) -> Optional[bool]:
         if self.start <= request < self.end:
             print(f"request {request} handled in handler 1")
             return True
+        return None
 
 
 class ConcreteHandler2(Handler):
@@ -76,6 +76,7 @@ def check_range(self, request: int) -> Optional[bool]:
         if start <= request < end:
             print(f"request {request} handled in handler 2")
             return True
+        return None
 
     @staticmethod
     def get_interval_from_db() -> Tuple[int, int]:

patterns/behavioral/command.py

@@ -20,7 +20,7 @@
 https://docs.djangoproject.com/en/2.1/ref/request-response/#httprequest-objects
 """
 
-from typing import Union
+from typing import List, Union
 
 
 class HideFileCommand:
@@ -30,7 +30,7 @@ class HideFileCommand:
 
     def __init__(self) -> None:
         # an array of files hidden, to undo them as needed
-        self._hidden_files = []
+        self._hidden_files: List[str] = []
 
     def execute(self, filename: str) -> None:
         print(f"hiding {filename}")
@@ -48,7 +48,7 @@ class DeleteFileCommand:
 
     def __init__(self) -> None:
         # an array of deleted files, to undo them as needed
-        self._deleted_files = []
+        self._deleted_files: List[str] = []
 
     def execute(self, filename: str) -> None:
         print(f"deleting {filename}")

patterns/behavioral/memento.py

@@ -5,6 +5,7 @@
 Provides the ability to restore an object to its previous state.
 """
 
+from typing import Callable, List
 from copy import copy, deepcopy
 
 
@@ -25,7 +26,7 @@ class Transaction:
     """
 
     deep = False
-    states = []
+    states: List[Callable[[], None]] = []
 
     def __init__(self, deep, *targets):
         self.deep = deep

patterns/behavioral/registry.py

@@ -1,6 +1,9 @@
+from typing import Dict
+
+
 class RegistryHolder(type):
 
-    REGISTRY = {}
+    REGISTRY: Dict[str, "RegistryHolder"] = {}
 
     def __new__(cls, name, bases, attrs):
         new_cls = type.__new__(cls, name, bases, attrs)

patterns/behavioral/specification.py

@@ -39,12 +39,9 @@ def not_specification(self):
 
 
 class AndSpecification(CompositeSpecification):
-    _one = Specification()
-    _other = Specification()
-
     def __init__(self, one, other):
-        self._one = one
-        self._other = other
+        self._one: Specification = one
+        self._other: Specification = other
 
     def is_satisfied_by(self, candidate):
         return bool(
@@ -54,12 +51,9 @@ def is_satisfied_by(self, candidate):
 
 
 class OrSpecification(CompositeSpecification):
-    _one = Specification()
-    _other = Specification()
-
     def __init__(self, one, other):
-        self._one = one
-        self._other = other
+        self._one: Specification = one
+        self._other: Specification = other
 
     def is_satisfied_by(self, candidate):
         return bool(
@@ -69,10 +63,8 @@ def is_satisfied_by(self, candidate):
 
 
 class NotSpecification(CompositeSpecification):
-    _wrapped = Specification()
-
     def __init__(self, wrapped):
-        self._wrapped = wrapped
+        self._wrapped: Specification = wrapped
 
     def is_satisfied_by(self, candidate):
         return bool(not self._wrapped.is_satisfied_by(candidate))

patterns/creational/borg.py

@@ -32,10 +32,11 @@
 *TL;DR
 Provides singleton-like behavior sharing state between instances.
 """
+from typing import Dict
 
 
 class Borg:
-    _shared_state = {}
+    _shared_state: Dict[str, str] = {}
 
     def __init__(self):
         self.__dict__ = self._shared_state

patterns/structural/flyweight.py

@@ -34,7 +34,7 @@ class Card:
     # Could be a simple dict.
     # With WeakValueDictionary garbage collection can reclaim the object
     # when there are no other references to it.
-    _pool = weakref.WeakValueDictionary()
+    _pool: weakref.WeakValueDictionary = weakref.WeakValueDictionary()
 
     def __new__(cls, value, suit):
         # If the object exists in the pool - just return it

setup.cfg

@@ -7,3 +7,7 @@ exclude = venv*
 filterwarnings =
     ; ignore TestRunner class from facade example
     ignore:.*test class 'TestRunner'.*:Warning
+
+[mypy]
+python_version = 3.8
+ignore_missing_imports = True